Construction and building tasks often require a suitable reference for establishing flatness, linearity or a common relationship of surface features. As examples among many different applications, a carpenter may use a linear reference tool to establish highpoints while planing a surface, or an installer may use a similar reference to establish low spots while finishing a wall. Typical extending straight edge tools are limited in length or do not create a continuous reference edge, and include a level. Levels are often used due to their straightness and finished edges, but the level function is not critical to many applications and including the level in a straight edge increases the tool cost.